1. Field of the Invention
This invention relates to a temperature estimation apparatus for an aeroplane gas turbine engine.
2. Description of the Related Art
In an aeroplane gas turbine engine equipped with a high-pressure turbine rotated by high-pressure gas injected from a combustion chamber of the engine and with a low-pressure turbine located downstream of the high-pressure turbine and rotated by low-pressure gas passed therethrough, it is preferable to detect the temperature at an inlet of the high-pressure turbine for preventing the overheat of the engine. However, since the inlet temperature is extremely high so that it is impossible to directly detect it, it is configured to detect inlet temperature of the low-pressure turbine downstream of the high-pressure turbine and based thereon, estimate the inlet temperature of the high-pressure turbine.
However, since it is difficult to keep a space for a temperature sensor at or in the vicinity of the inlet of the low-pressure turbine of the aeroplane gas turbine engine which is required to be compact, the inlet temperature of the high-pressure turbine can not be estimated based on the inlet temperature of the low-pressure turbine.
To cope with it, a temperature sensor is installed near an outlet of the low-pressure turbine and based on the outlet temperature of the low-pressure turbine, the inlet temperature of the high-pressure turbine is estimated, as taught by, for example, Japanese Laid-Open Patent Application No. 2002-106364.